This invention relates to a process for catalytically hydrogenating sulfolenes to sulfolanes. In another aspect, this invention relates to a process for hydrogenating sulfolenes to sulfolanes over a nickel catalyst. In a further aspect, this invention relates to treating sulfolenes so as to remove impurities which interfere with the subsequent catalytic hydrogenation of sulfolenes.
The catalytic hydrogenation of sulfolenes to sulfolanes is well known. Generally a supported nickel catalyst is employed. Also the removal of sulfur dioxide and other impurities from sulfolenes prior to the catalytic hydrogenation has been taught, such as in U.S. Pat. Nos. 3,345,384 and 4,286,099. However, there is an ever present need to develop new, more effective processes for removing impurities from sulfolenes and for hydrogenating sulfolenes.